Sesampainya di rumah, adik perempuan saya membersihkan monitor laptop dan menyimpan mouse di laci.

Sesampainya means something like upon arriving or when [someone] arrived.

In this sentence, Sesampainya di rumah means when she arrived home / upon arriving at home.

It is built from sampai (to arrive) with the pattern se- ... -nya, which often creates a time expression. So it does not simply mean arrival word-for-word; it functions more like an introductory time clause.

A very common near-synonym is setibanya di rumah, from tiba (to arrive).

The understood subject is normally the same as the subject of the main clause: adik perempuan saya.

So the sentence is understood as: When my younger sister arrived home, she cleaned the laptop monitor and put the mouse in the drawer.

Indonesian often leaves this kind of subject unstated when it is easy to understand from context.

If you wanted to make it fully explicit, you could say something like: Setelah adik perempuan saya sampai di rumah, ...

Here di is a preposition meaning in / at / on, so it is written as a separate word.

• di rumah = at home
• di laci = in the drawer

This is different from the prefix di- used in passive verbs, which is attached to the verb:

• dibersihkan = was cleaned
• disimpan = was stored/put away

So a useful rule is:

• di + place → separate
• di- + verb → attached

In Indonesian, possessors usually come after the noun.

So:

• rumah saya = my house
• adik perempuan saya = my younger sister
• laptop saya = my laptop

This is the normal pattern. English says my sister, but Indonesian says the equivalent of sister my.

Adik means a younger sibling.
Perempuan means female.

So adik perempuan specifically means younger sister.

This is different from:

• kakak perempuan = older sister
• adik laki-laki = younger brother
• kakak laki-laki = older brother

Indonesian often makes age distinction where English just says brother or sister.

Sometimes people simply say adik saya if the gender is already clear from context. Adding perempuan makes it explicit.

Bersih means clean. It is usually an adjective.

Membersihkan means to clean something. It is a transitive verb, so it takes an object:

• membersihkan monitor = to clean the monitor

So the relationship is roughly:

• bersih = clean
• membersihkan = to make clean / to clean

This is a very common pattern in Indonesian, where affixes turn a base word into a verb with a more specific grammatical role.

In Indonesian noun phrases, the main noun usually comes first, and the modifier comes after it.

So:

• monitor laptop = laptop monitor
• rumah sakit = hospital (literally house sick historically)
• meja makan = dining table

Here, monitor is the main noun, and laptop tells you what kind of monitor it is.

English often puts the modifier first; Indonesian usually puts it after.

Menyimpan often means to store, to keep, or to put away, not just to place.

So menyimpan mouse di laci suggests more than simply moving the mouse somewhere. It implies putting it in the drawer to keep it there.

Compare:

• menyimpan mouse di laci = put the mouse away in the drawer / store the mouse in the drawer
• meletakkan mouse di meja = place the mouse on the table
• menaruh mouse di meja = put the mouse on the table

So menyimpan has a stronger sense of putting something in its place or keeping it for later.

Yes, they are normal and commonly used.

• monitor and laptop are common loanwords.
• mouse is also commonly used for the computer device.
• laci means drawer and is a standard everyday Indonesian word.

For mouse, you may also see tetikus, which is an official Indonesian equivalent, but in everyday usage many speakers still say mouse.

So this sentence sounds very natural in modern Indonesian.

Indonesian verbs do not change the way English verbs do for tense. There is no verb ending here that means past.

The past meaning comes from context and the event sequence: upon arriving home, she cleaned the monitor and put away the mouse.

In other contexts, the same verbs could be translated differently:

• membersihkan = cleans / cleaned / will clean
• menyimpan = stores / stored / will store

If a speaker wants to make time clearer, they often add time words such as:

• tadi = earlier
• kemarin = yesterday
• besok = tomorrow
• sudah / telah = already

Indonesian does not normally use articles like English a, an, and the.

So:

• monitor laptop
• mouse
• laci

can be translated as a monitor, the monitor, a mouse, the mouse, a drawer, or the drawer, depending on context.

In this sentence, English naturally uses the because the objects sound specific in context: the laptop monitor and the drawer.

So nothing is missing in Indonesian; the language just handles definiteness differently.

It most naturally goes with menyimpan mouse.

So the sentence is understood as:

• she cleaned the laptop monitor
• and put the mouse in the drawer

It does not normally mean that she cleaned the monitor in the drawer.

This is because di laci comes right after menyimpan mouse, so it is read as the location/complement of that action. Word order helps show the connection.